Distal femoral knee prostheses

ABSTRACT

A set of distal femoral knee prostheses which are designed to be more narrow in medial/lateral dimensions with increasing anterior/posterior size than existing prostheses to more closely correspond to the physical anatomy of female patients. The prostheses are designed to have a substantially trapezoidal shape or profile when viewed distally which features a more pronounced narrowing of the medial/lateral dimensions beginning at the posterior end of the prostheses and progressing anteriorly to the anterior end of the prostheses. Additionally, the prostheses each include a reduced profile patellar sulcus and reduced profile anterior condyles to more closely conform to the anatomy of a resected femur, and also include sulcus tracking optimized to conform to female anatomy.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under Title 35, U.S.C. §119(e) ofU.S. Provisional Patent Application Ser. No. 60/750,613, entitled DistalFemoral Knee Prostheses, filed Dec. 15, 2005, and U.S. ProvisionalPatent Application Ser. No. 60/805,933, entitled Distal Femoral KneeProstheses, filed Jun. 27, 2006, the disclosures of which are eachhereby expressly incorporated herein by reference.

BACKGROUND

1. Field of the Invention

The present invention relates generally to orthopedic prosthetic devicesand, in particular, to distal femoral knee prostheses.

2. Description of the Related Art

Disease and trauma affecting the articular surfaces of a knee joint arecommonly effectively treated by surgically replacing the articulatingends of the femur and tibia with prosthetic femoral and tibial implantsor prostheses according to a procedure known as a total knee replacement(“TKR”) or a total knee arthroplasty (“TKA”). The femoral and tibialimplants are made of materials that exhibit a low coefficient offriction as they articulate against one another to restore normal kneefunction.

Although distal femoral knee prostheses are provided in a range ofvarying sizes and are selected by surgeons to best fit the anatomy of aparticular patient, improvements in the design of distal femoral kneeprostheses are desired.

SUMMARY

The present invention provides a set of distal femoral knee prostheseswhich are designed to be more narrow in medial/lateral (“M/L”)dimensions with increasing anterior/posterior (“A/P”) size than existingprostheses to more closely correspond to the physical anatomy of femalepatients. The prostheses are designed to have a substantiallytrapezoidal shape or profile when viewed distally which features a morepronounced narrowing of the M/L dimensions beginning at the posteriorend of the prostheses and progressing anteriorly to the anterior end ofthe prostheses. Additionally, the prostheses each include a reducedprofile patellar sulcus and reduced profile anterior condyles to moreclosely conform to the anatomy of a resected femur, and also includesulcus tracking which is optimized to conform to female anatomy.

In one form thereof, the present disclosure provides a set of distalfemoral prostheses particularly adapted for female anatomy, each femoralprosthesis including a distal nonarticulating surface having an anteriorend and a posterior end, including a plurality of standard aspect ratioprostheses respectively having increasingly greater overallanterior/posterior dimensions defined between points located mostanteriorly and most posteriorly on each prosthesis and havingincreasingly greater distal taper angles defined between a lateral lineconnecting the anterior end and the posterior end of the distalnonarticulating surface and a medial line connecting the anterior endand the posterior end of the distal nonarticulating surface on eachprosthesis; at least some of the prostheses having a distal taper anglegreater than or equal to approximately 21°.

In another form thereof, the present disclosure provides a set of distalfemoral prostheses particularly adapted for female anatomy, each femoralprosthesis including a distal nonarticulating surface having an anteriorend and a posterior end, including a plurality of standard aspect ratioprostheses each having an overall anterior/posterior dimension definedbetween points located most anteriorly and most posteriorly on eachprosthesis and a medial/lateral dimension defined between points locatedmost medially and most laterally at anterior/posterior locationssubstantially equidistant from the anterior end of the distalnonarticulating surface and the posterior end of the distalnonarticulating surface; at least some of the prostheses having anoverall anterior/posterior dimension and a medial/lateral dimensionfalling below a conceptual boundary defined by a line connecting a firstpoint and a second point, the first point having an approximately 52.0overall anterior/posterior dimension and an approximately 55.0medial/lateral dimension, and the second point having an approximately77.0 overall anterior/posterior dimension and an approximately 78.5medial/lateral dimension; wherein the line is defined by the followingequation: (medial/lateral dimension)=(0.94*overall anterior/posteriordimension)+6.12.

In yet another form thereof, the present disclosure provides a set ofdistal femoral prostheses particularly adapted for female anatomy, eachfemoral prosthesis including a distal nonarticulating surface having ananterior end and a posterior end, including a plurality of standardaspect ratio prostheses respectively having increasingly greater overallanterior/posterior dimensions defined between points located mostanteriorly and most posteriorly on each prosthesis and respectivelyhaving increasingly greater medial/lateral dimensions defined betweenpoints located most medially and most laterally at an anterior/posteriorlocation defined by the anterior end of the distal nonarticulatingsurface on each prosthesis; at least some of the prostheses having anoverall anterior/posterior dimension and a medial/lateral dimensionfalling below a conceptual boundary defined by a line connecting a firstpoint and a second point, the first point having an approximately 52.0overall anterior/posterior dimension and an approximately 50.0medial/lateral dimension, and the second point having an approximately77.0 overall anterior/posterior dimension and an approximately 70.5medial/lateral dimension; wherein the line is defined by the followingequation: (medial/lateral dimension)=(0.82*overall anterior/posteriordimension)+7.36.

In still another form thereof, the present disclosure provides a set ofdistal femoral prostheses particularly adapted for female anatomy, eachfemoral prosthesis including a distal nonarticulating surface and ananterior nonarticulating surface, including a plurality of standardaspect ratio prostheses respectively having increasingly greater overallanterior/posterior dimensions defined between points located mostanteriorly and most posteriorly on each prosthesis and respectivelyhaving increasingly greater medial/lateral dimensions defined betweenpoints located most medially and most laterally at an anterior/posteriorlocation defined by a distal most point on the anterior nonarticulatingsurface on each prosthesis; at least some of the prostheses having anoverall anterior/posterior dimension and a medial/lateral dimensionfalling below a conceptual boundary defined by a line connecting a firstpoint and a second point, the first point having an approximately 52.0overall anterior/posterior dimension and an approximately 40.1medial/lateral dimension, and the second point having an approximately77.0 overall anterior/posterior dimension and an approximately 53.5medial/lateral dimension; wherein the line is defined by the followingequation: (medial/lateral dimension)=(0.54*overall anterior/posteriordimension)+12.23.

In another form thereof, the present disclosure provides a set of distalfemoral prostheses particularly adapted for female anatomy, each femoralprosthesis including a distal nonarticulating surface and an anteriornonarticulating surface, including a plurality of prosthesesrespectively having increasingly greater overall anterior/posteriordimensions defined between points located most anteriorly and mostposteriorly on each prosthesis and respectively having increasinglygreater medial/lateral dimensions defined between points located mostmedially and most laterally at an anterior/posterior location defined bya distal most point on the anterior nonarticulating surface on eachprosthesis; at least some of the prostheses having an overallanterior/posterior dimension and a medial/lateral dimension fallingbelow a conceptual boundary defined by a line connecting a first pointand a second point, the first point having an approximately 52.0 overallanterior/posterior dimension and an approximately 40.3 medial/lateraldimension, and the second point having an approximately 77.0 overallanterior/posterior dimension and an approximately 51.8 medial/lateraldimension; wherein the line is defined by the following equation:(medial/lateral dimension)=(0.46*overall anterior/posteriordimension)+16.38.

In a still further form thereof, the present disclosure provides a setof distal femoral prostheses particularly adapted for female anatomy,each femoral prosthesis including a distal nonarticulating surfacehaving an anterior end and a posterior end, including a plurality ofprostheses each having an overall anterior/posterior dimension definedbetween points located most anteriorly and most posteriorly on eachprosthesis and a medial/lateral dimension defined between points locatedmost medially and most laterally at anterior/posterior locationssubstantially equidistant from the anterior end of the distalnonarticulating surface and the posterior end of the distalnonarticulating surface; at least some of the overall anterior/posteriordimensions and the medial/lateral dimensions falling within a conceptualboundary defined by an upper line and a lower line, the upper lineconnecting a first point and a third point, the lower line connecting asecond point and a fourth point, the first point having an approximately52.0 overall anterior/posterior dimension and an approximately 55.0medial/lateral dimension, the second point having an approximately 52.0overall anterior/posterior dimension and an approximately 47.0medial/lateral dimension, the third point having an approximately 77.0overall anterior/posterior dimension and an approximately 78.5medial/lateral dimension, and the fourth point having an approximately77.0 overall anterior/posterior dimension and an approximately 70.0medial/lateral dimension; wherein the upper line is defined by thefollowing equation: (medial/lateral dimension)=(0.94*overallanterior/posterior dimension)+6.12; and wherein the lower line isdefined by the following equation: (medial/lateraldimension)=(0.92*overall anterior/posterior dimension)−0.84.

In yet another form thereof, the present disclosure provides a set ofdistal femoral prostheses particularly adapted for female anatomy, eachfemoral prosthesis including a distal nonarticulating surface having ananterior end and a posterior end, including a plurality of standardaspect ratio prostheses respectively having increasingly greater overallanterior/posterior dimensions defined between points located mostanteriorly and most posteriorly on each prosthesis and havingincreasingly greater medial/lateral dimensions defined between pointslocated most medially and most laterally at an anterior/posteriorlocation substantially equidistant from the anterior end of the distalnonarticulating surface and the posterior end of the distalnonarticulating surface on each prosthesis; the medial/lateraldimensions of the prostheses respectively increasing at a first rate,the overall anterior/posterior dimensions respectively increasing at asecond rate, the first rate and the second rate defining a ratiosubstantially equal to or less than 0.89.

In still another form thereof, the present disclosure provides a set ofdistal femoral prostheses particularly adapted for female anatomy, eachfemoral prosthesis including a distal nonarticulating surface having ananterior end and a posterior end, including a plurality of prosthesesrespectively having increasingly greater overall anterior/posteriordimensions defined between points located most anteriorly and mostposteriorly on each prosthesis and having increasingly greatermedial/lateral dimensions defined between points located most mediallyand most laterally at an anterior/posterior location substantiallyequidistant from the anterior end of the distal nonarticulating surfaceand the posterior end of the distal nonarticulating surface on eachprosthesis; the medial/lateral dimensions of the prostheses respectivelyincreasing at a first rate, the overall anterior/posterior dimensionsrespectively increasing at a second rate, the first rate and the secondrate defining a ratio substantially equal to or less than 0.75.

In a further form thereof, the present disclosure provides a set ofdistal femoral prostheses particularly adapted for female anatomy,including a plurality of standard aspect ratio prostheses respectivelyhaving increasingly greater overall anterior/posterior dimensionsdefined between points located most anteriorly and most posteriorly oneach prosthesis and having increasingly greater medial/lateraldimensions defined between points located most medially and mostlaterally at an anterior/posterior location defined at a locationproximate the most posteriorly located point on each prosthesis; themedial/lateral dimensions of the prostheses respectively increasing at afirst rate, the overall anterior/posterior dimensions respectivelyincreasing at a second rate, the first rate and the second rate defininga ratio substantially equal to or less than 0.96.

In another form thereof, the present disclosure provides a set of distalfemoral prostheses particularly adapted for female anatomy, including aplurality of prostheses respectively having increasingly greater overallanterior/posterior dimensions defined between points located mostanteriorly and most posteriorly on each prosthesis and havingincreasingly greater medial/lateral dimensions defined between pointslocated most medially and most laterally at an anterior/posteriorlocation defined at a location proximate the most posteriorly locatedpoint on each prosthesis; the medial/lateral dimensions of theprostheses respectively increasing at a first rate, the overallanterior/posterior dimensions respectively increasing at a second rate,the first rate and the second rate defining a ratio substantially equalto or less than 0.84.

In still another form thereof, the present disclosure provides a set ofdistal femoral prostheses particularly adapted for female anatomy, eachfemoral prosthesis including a distal nonarticulating surface having ananterior end and a posterior end, including a plurality of standardaspect ratio prostheses respectively having increasingly greater overallanterior/posterior dimensions defined between points located mostanteriorly and most posteriorly on each prosthesis and respectivelyhaving increasingly greater medial/lateral dimensions defined betweenpoints located most medially and most laterally at an anterior/posteriorlocation defined by the anterior end of the distal nonarticulatingsurface on each prosthesis; the medial/lateral dimensions of theprostheses respectively increasing at a first rate, the overallanterior/posterior dimensions respectively increasing at a second rate,the first rate and the second rate defining a ratio substantially equalto or less than 0.78.

In yet another form thereof, the present disclosure provides a set ofdistal femoral prostheses particularly adapted for female anatomy, eachfemoral prosthesis including a distal nonarticulating surface having ananterior end and a posterior end, including a plurality of prosthesesrespectively having increasingly greater overall anterior/posteriordimensions defined between points located most anteriorly and mostposteriorly on each prosthesis and respectively having increasinglygreater medial/lateral dimensions defined between points located mostmedially and most laterally at an anterior/posterior location defined bythe anterior end of the distal nonarticulating surface on eachprosthesis; the medial/lateral dimensions of the prostheses respectivelyincreasing at a first rate, the overall anterior/posterior dimensionsrespectively increasing at a second rate, the first rate and the secondrate defining a ratio substantially equal to or less than 0.76.

In another form thereof, the present disclosure provides a set of distalfemoral prostheses particularly adapted for female anatomy, each femoralprosthesis including a distal nonarticulating surface and an anteriornonarticulating surface, including a plurality of standard aspect ratioprostheses respectively having increasingly greater overallanterior/posterior dimensions defined between points located mostanteriorly and most posteriorly on each prosthesis and respectivelyhaving increasingly greater medial/lateral dimensions defined betweenpoints located most medially and most laterally at an anterior/posteriorlocation defined by a distal most point on the anterior nonarticulatingsurface on each prosthesis; the medial/lateral dimensions of theprostheses respectively increasing at a first rate, the overallanterior/posterior dimensions respectively increasing at a second rate,the first rate and the second rate defining a ratio substantially equalto or less than 0.44.

In a further form thereof, the present disclosure provides a set ofdistal femoral prostheses particularly adapted for female anatomy, eachfemoral prosthesis including a distal nonarticulating surface having ananterior end and a posterior end, including a plurality of prosthesesrespectively having increasingly greater overall anterior/posteriordimensions defined between points located most anteriorly and mostposteriorly on each prosthesis and having increasingly greater distaltaper angles defined between a lateral line connecting the anterior endand the posterior end of the distal nonarticulating surface and a medialline connecting the anterior end and the posterior end of the distalnonarticulating surface on each prosthesis; the distal taper angles ofthe prostheses respectively increasing at a first rate, the overallanterior/posterior dimensions of the prostheses respectively increasingat a second rate, the first rate and the second rate defining a ratiosubstantially equal to or greater than 0.22.

In still another form thereof, the present disclosure provides a set ofdistal femoral prostheses particularly adapted for female anatomy, eachfemoral prosthesis including a distal nonarticulating surface having ananterior end and a posterior end, including a plurality of prosthesesrespectively having increasingly greater overall anterior/posteriordimensions defined between points located most anteriorly and mostposteriorly on each prosthesis and having increasingly greater distaltaper angles defined between a lateral line connecting the anterior endand the posterior end of the distal nonarticulating surface and a medialline connecting the anterior end and the posterior end of the distalnonarticulating surface on each prosthesis; at least some of the overallanterior/posterior dimensions and the distal taper angles falling withina conceptual boundary defined by an upper boundary and a lower boundary,the upper boundary defined by a line connecting a first point and athird point, the lower boundary defined by a line connecting a secondpoint and a fourth point, the first point having an approximately 52.0overall anterior/posterior dimension and an approximately 27.0° distaltaper angle, the second point having an approximately 58.0 overallanterior/posterior dimension and an approximately 22.5° distal taperangle, the third point having an approximately 77.0 overallanterior/posterior dimension and an approximately 32.0° distal taperangle, and the fourth point having an approximately 77.0 overallanterior/posterior dimension and an approximately 26.0° distal taperangle.

In yet another form thereof, the present disclosure provides a set ofdistal femoral prostheses particularly adapted for female anatomy, eachfemoral prosthesis including a distal nonarticulating surface having ananterior end and a posterior end, including a plurality of prosthesesrespectively having increasingly greater overall anterior/posteriordimensions defined between points located most anteriorly and mostposteriorly on each prosthesis and having increasingly greater distaltaper angles defined between a lateral line connecting the anterior endand the posterior end of the distal nonarticulating surface and a medialline connecting the anterior end and the posterior end of the distalnonarticulating surface on each prosthesis; at least some of the overallanterior/posterior dimensions and the distal taper angles falling withina conceptual boundary defined by an upper boundary and a lower boundary,the upper boundary defined by a line connecting a first point and athird point, the lower boundary defined by a line connecting a secondpoint and a fourth point, the first point having an approximately 52.0overall anterior/posterior dimension and an approximately 34.0° distaltaper angle, the second point having an approximately 58.0 overallanterior/posterior dimension and an approximately 22.5° distal taperangle, the third point having an approximately 77.0 overallanterior/posterior dimension and an approximately 32.0° distal taperangle, and the fourth point having an approximately 77.0 overallanterior/posterior dimension and an approximately 26.0° distal taperangle.

In a further form thereof, the present disclosure provides a distalfemoral prosthesis, including a non-articulating surface including adistal plane and an anterior non-articular surface; lateral and medialanterior condyles; a patellar sulcus defined between the condyles, thepatellar sulcus having a maximum thickness between approximately 2.5 mmand 3.2 mm between an anterior most point on the sulcus and the anteriornon-articular surface.

In another form thereof, the present disclosure provides a distalfemoral prosthesis, including a non-articulating surface including adistal plane and an anterior non-articular surface; lateral and medialanterior condyles each defining an anterior articular surface, at leastone of the condyles having a maximum thickness between approximately 4.0mm and 6.1 mm between an anterior most point on the anterior articularsurface of the condyle and the anterior non-articular surface.

In yet another form thereof, the present disclosure provides a distalfemoral prosthesis, including a patellar sulcus disposed between lateraland medial anterior condyles of the prosthesis, the sulcus having an endpoint; a non-articulating surface having a distal plane; and alateralization distance defined at the end point between a first lineextending from an intersection of the distal plane and the sulcus andthe end point, the lateralization distance greater than 5.0 mm.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention itself will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a side view of an exemplary distal femoral prosthesis inaccordance with the present invention;

FIG. 2 is another side view of the prosthesis of FIG. 1, illustratingcertain dimensions thereof;

FIG. 3 is a distal view of the prosthesis of FIG. 2, viewed along line3-3 of FIG. 2 and shown superimposed on a known prosthesis;

FIG. 4 further illustrates the anatomical M/L vs. A/P dimensionalrelationship of the prosthesis of FIG. 3 at dimension “B-B”;

FIG. 5 is a graph illustrating a representative anatomical mid-box M/Lvs. A/P dimensional relationship with respect to male and female femursof various size;

FIG. 5A is a view of an anatomic overall A/P dimension for arepresentative femur;

FIG. 5B is a view of an anatomic mid-box M/L dimension for arepresentative femur;

FIG. 6 is a graph of mid-box M/L vs. overall A/P for prostheses designedin accordance with the present invention as compared with several knownprostheses;

FIG. 7 is a graph of anterior M/L along a dimension “B-B” vs. overallA/P for prostheses designed in accordance with the present invention ascompared with several known prostheses;

FIG. 8 is a graph of posterior M/L vs. overall A/P for prosthesesdesigned in accordance with the present invention as compared withseveral known prostheses;

FIG. 9 is a graph of the ratio of (mid-box M/L/overall A/P) vs. overallA/P for the prostheses of FIG. 6;

FIG. 10 is a graph of the ratio of (anterior M/L along dimension“B-B”/overall A/P) vs. overall A/P for the prostheses of FIG. 7;

FIG. 11 is a graph of the ratio of (posterior M/L/overall A/P) vs.overall A/P for the prostheses of FIG. 8;

FIG. 12 is a distal view of an exemplary prosthesis designed inaccordance with the present invention, shown superimposed on a knownprosthesis and illustrating the profiles and the distal taper angles ofsame;

FIG. 13 is a graph of distal taper angle vs. overall A/P for prosthesesdesigned in accordance with the present invention as compared withseveral known prostheses;

FIG. 14 is a distal view of an exemplary prosthesis;

FIG. 15 is a side view of the prosthesis of FIG. 14, illustrating therecessed patellar sulcus thereof as compared with a known prosthesis;

FIG. 16 is another side view of the prosthesis of FIG. 14, illustratingthe reduced profile of the anterior condyles thereof as compared with aknown prosthesis;

FIG. 17A is an A/P view of a known prosthesis having conventional sulcustracking;

FIG. 17B is an A/P view of an exemplary prosthesis in accordance withthe present invention having a more lateralized sulcus tracking;

FIG. 18 is a graph of A-A M/L vs. overall A/P for prostheses designed inaccordance with the present invention as compared with several knownprostheses; and

FIG. 19 is a graph of the ratio of (A-A M/L/overall A/P) vs. overall A/Pfor the prostheses of FIG. 18.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate exemplary embodiments of the invention, and suchexemplifications are not to be construed as limiting the scope of theinvention any manner.

DETAILED DESCRIPTION

As used herein, the following directional definitions apply. Anteriorand posterior mean nearer the front or nearer the rear of the body,respectively. Thus, with respect to the prostheses described herein,anterior refers to that portion of the knee that is nearer the front ofthe body, when the leg is in an extended position. Proximal and distalmean nearer to or further from the root of a structure, respectively.For example, the distal femur is a part of the knee joint while theproximal femur is part of the hip joint. Finally, the adjectives medialand lateral mean nearer the sagittal plane or further from the sagittalplane, respectfully. The sagittal plane is an imaginary vertical planethrough the middle of the body that divides the body into right and lefthalves.

Distal femoral knee prostheses made in accordance with the presentinvention are intended to be used to restore knee joint function inpatients with severe pain and disability due, for example, to Rheumatoidarthritis, osteoarthritis, traumatic arthritis polyarthritis; collagendisorders, and/or avascular necrosis of the femoral condyle;post-traumatic loss of joint configuration, particularly when there ispatellofemoral erosion, dysfunction or prior patellectomy; moderatevalgus, varus, flexion deformities, or other conditions.

Referring initially to FIG. 1, a distal femoral prosthesis 50 for aTKR/TKA according to one embodiment of the present invention is shown,and generally includes an external articulating surface 52 and a bonecontacting non-articulating internal surface 54. Articulating surface 52includes an anterior articulating surface 56, a distal articulatingsurface 58, a lateral posterior condylar articulating surface 60, and amedial posterior condylar articulating surface 62. Prosthesis 50 may bemade of any biocompatible material having the mechanical propertiesnecessary to function as a human knee distal femoral prosthesis.Preferably, prosthesis 50 is made of titanium, titanium alloy, cobaltchrome alloy, stainless steel, or a ceramic. Referring additionally toFIG. 3, prosthesis 50 further includes patellar flange 64 includinglateral and medial anterior condyles 66 and 68, respectively, as well aspatellar sulcus 70 disposed between lateral and medial anterior condyles66 and 68. Prosthesis also includes lateral and medial posteriorcondyles 72 and 74, respectively.

Referring to FIG. 1, the internal non-articulating portion 54 ofprosthesis 50 is adapted to receive a resected distal femur. Thesurgical cuts made to the distal femur can be made by any means, in anysequence and in any configuration known to those of skill in the art ofknee arthroplasty. Exemplary cut guides and processes for resecting thedistal femur are shown and described in U.S. patent application Ser. No.11/151,062, entitled ADJUSTABLE CUT GUIDE, filed on Jun. 13, 2005 andU.S. patent application Ser. No. 11/154,774, entitled MULTI-POSITIONABLECUT GUIDE, filed on Jun. 16, 2005, assigned to the assignee of thepresent invention, the disclosures of which are expressly incorporatedherein by reference.

In a preferred embodiment, prosthesis 50 comprises a plurality ofchamfer surfaces corresponding to a plurality of chamfer surfaces or“box cuts” made in the distal femur. Non-articular surface 54 maycomprise a porous metal surface or any surface likely to promote thegrowth of bone therein. Non-articular surface 54 of prosthesis 50preferably comprises anterior non-articular surface 76, distal anteriornon-articular surface 78, distal non-articular surface 80, two distalposterior non-articular surfaces 82, and two posterior non-articularsurfaces 84.

Distal non-articular surface 80 is generally flat and adapted to receivethe distal-most surface of the resected femur. Distal non-articularsurface 80 comprises an anterior end and a posterior end. The anteriorend of distal non-articular surface 80 abuts one end of distal anteriornon-articular surface 78, which surface 78 also includes an anterior endand a posterior end. Surface 78 extends from surface 80 anteriorly andsuperiorly such that an obtuse angle is formed between surfaces 78 and80. Anterior non-articular surface 76 extends superiorly from theanterior end of surface 78.

The posterior end of distal non-articular surface 80 abuts one end ofeach distal posterior non-articular surface 82, which surfaces 82 alsoinclude an anterior end and a posterior end. Surfaces 82 extend fromsurface 80 posteriorly and superiorly such that an obtuse angle isformed between surfaces 82 and 80. Posterior non-articular surfaces 84extend superiorly from the posterior ends of surfaces 82, respectively.

As discussed in detail below, for many patients, particularly femalepatients, it is desirable to construct a set of prostheses 50 of varyingsize wherein the medial/lateral (“M/L”) width dimensions of theprostheses correspond more closely to the actual anatomical M/L widthdimensions of the female femur and articulating surfaces. As describedbelow, prostheses 50 addresses this concern by offering the surgeon aset of narrower prostheses in the M/L dimensions for a given set ofanterior/posterior (“A/P”) prosthesis sizes which will allow the surgeonto use a prosthesis with both a correct A/P size and more accurate andoptimized M/L dimensions to provide optimal prosthesis sizing and jointkinematics as compared to conventional prostheses.

In FIG. 3, the profile 86 of prosthesis 50 is superimposed upon profile88 of a known prosthesis. As described in detail below, prosthesis 50has a unique, substantially trapezoidal shape or profile 86 when vieweddistally with a more pronounced narrowing of the M/L dimensions ascompared to the shape or profile 88 of a known prosthesis starting, withreference to the resected femur, at the posterior distal facet andprogressing anteriorly to the anterior distal facet. Referring to FIGS.2 and 3, prosthesis 50 is shown and is characterized below withreference to the following directions: anterior “A”, posterior “P”,distal “D”, proximal “PR”, medial “M” and lateral “L”, as well as thefollowing dimensions. Dimension “Posterior” is the M/L width at thewidest point across the posterior condyles 72, 74 of prosthesis 50.Dimension “C-C” is the M/L width at the junction of the posterior distalfacet and the distal plane, i.e., the M/L width along the intersectionbetween distal non-articular surface 80 and distal posteriornon-articular surfaces 82. Dimension “B-B” is the M/L width at thejunction of the distal plane and the distal anterior facet, i.e., theM/L width along the intersection between distal non-articular surface 80and distal anterior non-articular surface 78. Dimension “A-A” is the M/Lwidth at the junction of the distal anterior facet and the posteriorside of the anterior flange, i.e., the M/L width along the intersectionof distal anterior non-articular surface 78 and anterior non-articularsurface 76. Dimension “MB” is the M/L width at a “mid-box” point ofprosthesis 50, i.e., along a line located on distal non-articularsurface 80 substantially midway between Dimension C-C and Dimension B-B.

As described below, the profiles of a set of prostheses 50 can also bedescribed in terms of an increasing narrowing of the M/L dimensionsrelative to known prostheses on a per size basis. It has been observedthat, for given female femurs, for example, the M/L dimensions aresometimes smaller than those of known prostheses of the proper A/Pdimension. This discrepancy is small on the smaller A/P size prosthesesand increases as the A/P size increases. For example, referring to FIG.5, a representative mid-box M/L vs. A/P dimensional relationship withrespect to the actual human anatomy of distal femurs for males andfemales is shown. Representative female data is generally groupedtogether at lower values of mid-box M/L and representative male data isgenerally grouped together at higher values of mid-box M/L. Best fitlines for female and male data have been included on FIG. 5 to show thegeneral trend of representative mid-box M/L dimensions. As may be seenfrom FIG. 5, there exists a clear distinction between the representativeM/L dimension vs. the A/P dimension for a female distal femur ascompared to a male distal femur. FIGS. 5A and 5B show exemplary anatomicoverall A/P and mid-box M/L dimensions for a representative femur.

In FIG. 2, the overall A/P (“Overall A/P”) dimension is the distancebetween two lines perpendicular to distal non-articular surface 80 thatpass through the most posterior point on the posterior face of exteriorarticulating surface 58 and through the most anterior point on theanterior face of exterior articulating surface 58, respectively. FIG. 2also shows a dashed outline of a resected femur with prosthesis 50positioned thereon.

As an exemplary comparison, the dimensions “Posterior”, “B-B”, “A-A”,and “Overall A/P” and the ratios of these values for conventionalprostheses (“Conventional 1”, including five increasing sizes C throughG) are compared with corresponding dimensions and ratios of a set ofprostheses designed in accordance with the present invention(“Embodiment 1”, including five increasing sizes C through G). Thesevalues are presented in Table 1 below. Unless otherwise indicated, allnumerical dimensional values presented herein are in millimeters (“mm”).

TABLE 1 Overall Overall SIZE A/P “Post.” “B-B” “A-A” A/P “Post.” “B-B”“A-A” Embodiment 1 Conventional 1 C 52.2 58.0 49.6 41.1 53.5 60.0 53.645.1 D 56.3 61.3 51.5 42.6 57.6 64.0 55.8 46.5 E 60.2 64.5 53.5 43.761.5 68.0 59.3 49.1 F 64.2 67.9 55.4 45.0 65.4 72.0 63.2 52.0 G 69.271.0 57.3 46.3 70.4 76.5 67.3 56.2 Embodiment 1 - Conventional 1 -M/L/“Overall M/L/“Overall A/P” RATIOS A/P” RATIOS C 52.2 1.11 0.95 0.7953.5 1.12 1.00 0.84 D 56.3 1.09 0.92 0.76 57.6 1.11 0.97 0.81 E 60.21.07 0.89 0.73 61.5 1.11 0.96 0.80 F 64.2 1.06 0.86 0.70 65.4 1.10 0.970.79 G 69.2 1.03 0.83 0.67 70.4 1.09 0.96 0.80

Table 2 below sets forth the results of a first order equation fit todata sets for several sets of prostheses including Conventional 1,Conventional 2 (which is similar to Conventional 1), Embodiment 1,Embodiment 2 (which is similar to Embodiment 1), as well as five othersets of known competitive prostheses, designated Competitive 1,Competitive 2, Competitive 3, Competitive 4, and Competitive 5. The datasets include Posterior M/L vs. Overall A/P and the Ratio (Posterior M/Lvs. Overall A/P) vs. Overall A/P.

TABLE 2 Ratio (Posterior M/ Posterior M/L L/Overall A/P) vs. Overall A/Pvs. Overall A/P Best fit regression line Best fit regression lineEquation Slope Equation Slope Conventional 1 y = 0.9811x + 7.595 0.9811y = −0.002x + 1.2277 −0.0020 Conventional 2 y = 0.9878x + 6.0634 0.9878y = −0.0015x + 1.1798 −0.0015 Embodiment 1 y = 0.8036x + 16.228 0.8036 y= −0.0044x + 1.3431 −0.0044 Embodiment 2 y = 0.809x + 14.987 0.8090 y =−0.0039x + 1.2965 −0.0039 Competitive 1 y = 0.9411x + 7.1008 0.9411 y =−0.0016x + 1.1565 −0.0016 Competitive 2 y = 0.987x + 6.8225 0.9870 y =−0.0017x + 1.2015 −0.0017 Competitive 3 y = 0.976x + 5.7825 0.9760 y =−0.0013x + 1.1521 −0.0013 Competitive 4 y = 0.9757x + 6.6279 0.9757 y =−0.0016x + 1.1836 −0.0016 Competitive 5 y = 0.9336x + 11.318 0.9336 y =−0.0031x + 1.3111 −0.0031

From the data in Table 2, it may be seen that there is a difference inthe slopes of the sets of prostheses of Embodiments 1 and 2 as comparedto the slopes of the sets of the known prostheses. In particular, it maybe seen from the data in Table 2 that the sets of prostheses ofEmbodiments 1 and 2 have a narrowing posterior M/L dimension withincreasing A/P size, as indicated by slopes less than 0.93, for example,as opposed to a substantially parallel or one-to-one relationshipbetween the posterior M/L dimension and the A/P dimension withincreasing A/P size as in the sets of known prostheses, as indicated byslopes of 0.93 and above. Thus, in the sets of known prostheses, theposterior M/L dimension and the A/P dimension increase at substantiallythe same rate with increasing A/P size. Also, the slope of the ratio(posterior M/L/overall A/P) vs. overall A/P is less than −0.0032 for thesets of prostheses of Embodiments 1 and 2 while the corresponding slopefor the known sets of prostheses is greater than −0.0032, indicatingthat the sets of prostheses of Embodiments 1 and 2 have an increasinglymore pronounced narrowing of the posterior M/L dimension with increasingA/P size. In this manner, the sets of prostheses designed in accordancewith the present invention offer a surgeon a unique combination ofimplant posterior M/L widths with varying A/P size for an overall systemor set of prostheses, wherein such sets of prostheses are moreanatomically optimized for the female anatomy as compared with the setsof known prostheses.

Table 3 below sets forth the results of a first order equation fit todata sets for several sets of prostheses including Conventional 1,Conventional 2 (which is similar to Conventional 1), Embodiment 1,Embodiment 2 (which is similar to Embodiment 1), as well as five othersets of known competitive prostheses, designated Competitive 1,Competitive 2, Competitive 3, Competitive 4, and Competitive 5. The datasets include B-B M/L vs. Overall A/P and the Ratio (B-B M/L vs. OverallA/P) vs. Overall A/P.

TABLE 3 Ratio (Anterior M/L Anterior M/L “B-B” “B-B”/Overall A/P) vs.Overall A/P vs. Overall A/P Best fit regression line Best fit regressionline Equation Slope Equation Slope Conventional 1 y = 0.834x + 8.37680.8340 y = −0.0023x + 1.112 −0.0023 Conventional 2 y = 0.8432x + 6.90030.8432 y = −0.0018x + 1.0681 −0.0018 Embodiment 1 y = 0.4626x + 25.0120.4626 y = −0.0071x + 1.3173 −0.0071 Embodiment 2 y = 0.4626x + 25.0120.4626 y = −0.0066x + 1.2797 −0.0066 Competitive 1 y = 0.9062x + 3.23060.9062 y = −0.0007x + 1.0017 −0.0007 Competitive 2 y = 0.8057x + 12.5880.8057 y = −0.0031x + 1.2033 −0.0031 Competitive 3 y = 0.893x + 5.53810.8930 y = −0.0012x + 1.0578 −0.0012 Competitive 4 y = 1.0588x + 0.17311.0588 y = −0.0001x + 1.0697 −0.0001 Competitive 5 y = 0.7937x + 12.2180.7937 y = −0.0036x + 1.217 −0.0036

From the data in Table 3, it may be seen that there is a significantdifference in slope for the sets of prostheses of Embodiments 1 and 2 ascompared with the slopes of the known sets of prostheses. The magnitudesof the anterior M/L “B-B” values for a given A/P dimension are morepronounced, i.e., the variance in width at dimension B-B, namely, ananterior width, over various A/P sizes between the sets of prostheses ofEmbodiments 1 and 2 and the known sets of prostheses is moredramatically pronounced. Specifically, sets of prostheses of Embodiments1 and 2 have a narrowing anterior M/L dimension with increasing A/Psize, as indicated by slopes less than 0.78, for example, as opposed toa substantially parallel or one-to-one relationship between the anteriorM/L dimension and the A/P dimension with increasing A/P size as in thesets of known prostheses, as indicated by slopes of 0.78 and above.Thus, in the sets of known prostheses, the anterior M/L dimension andthe A/P dimension increase at substantially the same rate withincreasing A/P size. Also, the slope of the ratio (anterior M/L“B-B”/overall A/P) vs. overall A/P is greater than −0.0038 for the setsof prostheses of Embodiments 1 and 2, while the corresponding slope forthe known sets of prostheses is less than −0.0038, indicating that thesets of prostheses of Embodiments 1 and 2 have increasingly morepronounced narrowing of the anterior M/L “B-B” dimension with increasingA/P size. In this manner, the prostheses designed in accordance with thepresent invention offer a surgeon a unique combination of implant M/Lwidths as an overall system of prostheses, wherein such sets ofprostheses are more anatomically optimized for the female anatomy ascompared with the sets of known prostheses.

As another exemplary comparison, the dimensions “Posterior”, “MB”,“B-B”, and “Overall A/P” for conventional prostheses (“Conventional 3”,“Conventional 4”, and “Conventional 5” including five increasing sizes Cthrough G) are compared with corresponding dimensions of a set ofprostheses designed in accordance with the present invention(“Embodiment 3”, “Embodiment 4”, and “Embodiment 5” including fiveincreasing sizes C through G). In one embodiment, the values forConventional 5 and Embodiment 5 may be average values of Conventionals 3and 4 and Embodiments 3 and 4, respectively. These values are presentedin Table 4 below.

TABLE 4 SIZE Overall A/P Posterior MB B-B Overall A/P Posterior MB B-BEmbodiment 4 Conventional 4 C 53.3 58.0 55.9 50.2 54.4 60.0 58.6 53.6 D57.5 61.4 58.4 52.0 58.6 64.0 62.1 55.8 E 61.2 64.7 60.8 54.0 62.5 68.065.9 59.3 F 65.3 68.1 63.5 56.0 66.5 72.0 70.2 63.2 G 70.4 71.5 66.058.0 71.5 76.5 74.0 67.3 Embodiment 3 Conventional 3 C 52.3 58.0 55.950.2 53.5 60.0 58.6 53.6 D 56.4 61.4 58.4 52.0 57.6 64.0 62.0 55.7 E60.2 64.7 60.8 54.0 61.5 68.0 65.9 59.3 F 64.2 68.1 63.5 56.0 65.5 72.070.2 63.2 G 69.4 71.5 66.0 58.0 70.5 76.5 74.0 67.2 Embodiment 5Conventional 5 C 52.8 58.0 55.9 50.2 54.0 60.0 58.6 53.6 D 56.9 61.458.4 52.0 58.1 64.0 62.0 55.8 E 60.7 64.7 60.8 54.0 62.0 68.0 65.9 59.3F 64.8 68.1 63.5 56.0 66.0 72.0 70.2 63.2 G 69.9 71.5 66.0 58.0 71.076.5 74.0 67.3

FIG. 6 is a graph of the dimension mid-box M/L vs. overall A/P for thefollowing sets of prostheses, each in increasing sizes C through G:Conventional 5, Embodiment 5, as well as eight other sets of knowncompetitive prostheses, designated Competitive 1, Competitive 2,Competitive 3, Competitive 4, Competitive 5, Competitive 6, Competitive7, and Competitive 8.

FIG. 7 is a graph of the dimension B-B M/L vs. overall A/P for thefollowing sets of prostheses, each in increasing sizes C through G:Conventional 5, Embodiment 5, as well as eight other sets of knowncompetitive prostheses, designated Competitive 1, Competitive 2,Competitive 3, Competitive 4, Competitive 5, Competitive 6, Competitive7, and Competitive 8.

FIG. 8 is a graph of the dimension Posterior M/L vs. overall A/P for thefollowing sets of prostheses, each in increasing sizes C through G:Conventional 5, Embodiment 5, as well as eight other sets of knowncompetitive prostheses, designated Competitive 1, Competitive 2,Competitive 3, Competitive 4, Competitive 5, Competitive 6, Competitive7, and Competitive 8.

Table 5 below sets forth the results of a first order equation fit toeach of the data sets shown in FIGS. 6, 7, and 8 as well as for the datasets of Embodiments 3 and 4 and Conventional 3 and 4 in Table 4.

TABLE 5 Posterior Mid-box M/L vs. M/L vs. B-B M/L vs. Overall A/POverall A/P Overall A/P Best Fit Best Fit Best Fit Regression RegressionRegression Line Line Line Implant Slope y-Intercept Slope y-InterceptSlope y-Intercept Conventional 3 0.98 7.53 0.93 8.63 0.83 8.35Conventional 4 0.98 6.82 0.93 8.02 0.83 7.66 Conventional 5 0.98 7.170.93 8.32 0.83 8.01 Embodiment 3 0.80 16.31 0.60 24.89 0.46 26.02Embodiment 4 0.80 15.51 0.60 24.30 0.46 25.55 Embodiment 5 0.80 15.910.60 24.59 0.46 25.79 Competitive 1 1.06 1.27 1.01 3.36 0.94 1.61Competitive 2 0.99 6.82 1.09 −1.10 0.80 12.80 Competitive 3 0.98 5.780.91 11.72 0.83 10.13 Competitive 4 0.98 6.63 1.02 3.40 1.06 0.17Competitive 5 0.90 13.67 0.91 11.72 0.82 10.34 Competitive 6 1.06 0.611.08 −0.70 1.06 −4.03 Competitive 7 0.86 19.80 0.77 19.86 0.78 9.00Competitive 8 0.91 −0.64 0.91 −1.64 0.91 −2.64

From the data in Table 5, it may be seen that there is a difference inthe slopes of the sets of prostheses of Embodiments 3, 4, and 5 ascompared to the slopes of the sets of the known prostheses. Inparticular, it may be seen from the data in Table 5 that the sets ofprostheses of Embodiments 3, 4, and 5 have a narrowing posterior M/Ldimension with increasing A/P size, as indicated by slopes less thanapproximately 0.85, for example, as opposed to a substantially parallelor one-to-one relationship between the posterior M/L dimension and theA/P dimension with increasing A/P size as in the sets of knownprostheses, as indicated by slopes of 0.86 and above. In exemplaryembodiments, the slope of posterior M/L dimension with increasing A/Psize for prostheses 50 may be as small as approximately 0.50, 0.55,0.60, or 0.65 or as large as approximately 0.85, 0.84, 0.83, 0.81, 0.80,0.75, or 0.70. In an exemplary embodiment, the slope of posterior M/Ldimension with increasing A/P size for prostheses 50 is approximately0.80. Thus, the posterior M/L dimension for prostheses 50 increases at alesser rate than the corresponding overall A/P dimension. In contrast,in the sets of known prostheses, the posterior M/L dimension and the A/Pdimension increase at substantially the same rate with increasing A/Psize. In this manner, the sets of prostheses designed in accordance withthe present invention offer a surgeon a unique combination of implantposterior M/L widths with varying A/P size for an overall system or setof prostheses, wherein such sets of prostheses are more anatomicallyoptimized for the female anatomy as compared with the sets of knownprostheses.

Furthermore, from the data in Table 5, it may be seen that there is asignificant difference in slope for the sets of prostheses ofEmbodiments 3, 4, and 5 as compared with the slopes of the known sets ofprostheses when looking at the B-B and MB dimensions. The magnitudes ofthe B-B values and MB values for a given A/P dimension are morepronounced, i.e., the variance in width at dimension B-B or MB overvarious A/P sizes between the sets of prostheses of Embodiments 3, 4,and 5 and the known sets of prostheses is more dramatically pronounced.

Specifically, sets of prostheses of Embodiments 3, 4, and 5 have anarrowing B-B M/L dimension with increasing A/P size, as indicated byslopes less than approximately 0.77, for example, as opposed to asubstantially parallel or one-to-one relationship between the B-B M/Ldimension and the A/P dimension with increasing A/P size as in the setsof known prostheses, as indicated by slopes of 0.78 and above. Inexemplary embodiments, the slope of the B-B M/L dimension withincreasing A/P size for prostheses 50 may be as small as approximately0.30, 0.35, 0.40, or 0.45 or as large as 0.77, 0.76, 0.75, 0.74, 0.72,0.70, 0.65, 0.60, or 0.50. In an exemplary embodiment, the slope is ofthe B-B M/L dimension with increasing A/P size for prostheses 50 isapproximately 0.46. Thus, the B-B M/L dimension for prostheses 50increases at a lesser rate than the corresponding overall A/P dimension.In contrast, in the sets of known prostheses, the B-B M/L dimension andthe A/P dimension increase at substantially the same rate withincreasing A/P size.

Furthermore, sets of prostheses of Embodiments 3, 4, and 5 have anarrowing MB M/L dimension with increasing A/P size, as indicated byslopes less than 0.76, for example, as opposed to a substantiallyparallel or one-to-one relationship between the MB M/L dimension and theA/P dimension with increasing A/P size as in the sets of knownprostheses, as indicated by slopes of 0.77 and above. In exemplaryembodiments, the slope of the MB M/L dimension with increasing A/P sizefor prostheses 50 may be as small as approximately 0.40, 0.45, 0.50,0.55, or 0.57 or as large as approximately 0.76, 0.75, 0.74 0.73, 0.72,0.71, 0.70, 0.65, or 0.60. In an exemplary embodiment, the slope of theMB M/L dimension with increasing A/P size for prostheses 50 isapproximately 0.60. Thus, the MB M/L dimension for prostheses 50increases at a lesser rate than the corresponding overall A/P dimension.In contrast, in the sets of known prostheses, the MB M/L dimension andthe A/P dimension increase at substantially the same rate withincreasing A/P size.

In this manner, the prostheses designed in accordance with the presentinvention offer a surgeon a unique combination of implant M/L widths asan overall system of prostheses, wherein such sets of prostheses aremore anatomically optimized for the female anatomy as compared with thesets of known prostheses.

Referring again to FIG. 6, the range of values for Embodiment 5generally falls within the lines of a conceptual boundary, such as aparallelogram, as shown in solid dashed lines. Clearly, no other knownprostheses have MB M/L dimensions that fall within this range of valuesfor the MB M/L dimensions and corresponding Overall A/P dimensions. Theparallelogram is essentially defined by four points defined bycoordinates given by (Overall A/P dimension, MB Dimension): A firstpoint or upper left corner (“First Point”)—(52.0, 55.0); A second pointor lower left corner (“Second Point”)—(52.0, 47.0); A third point orupper right corner (“Third Point”)—(77.0, 78.5); and a fourth point orlower right corner (“Fourth Point”)—(77.0, 70.0). Thus, the upperboundary of the parallelogram defined by First Point and Third Point maybe given by the equation MB M/L=0.94*Overall A/P+6.12 and the lowerboundary defined by Second Point and Fourth Point may be given by theequation MB M/L=0.92*Overall A/P−0.84.

As set forth in Table 6 below, the Overall A/P dimensions and the ratiosof the dimensions “Posterior”, “MB”, and “B-B” vs. “Overall A/P” aregiven for Embodiments 3, 4, and 5 as well as for conventional prosthesesConventional 3, 4, and 5.

TABLE 6 Ratio Ratio Ratio Ratio Ratio Ratio (Posterior (MB (B-B(Posterior (MB (B-B M/L/ M/L/ M/L/ M/L/ M/L/ M/L/ Overall OverallOverall Overall Overall Overall Overall SIZE A/P A/P) A/P) A/P) OverallA/P A/P) A/P) A/P) Embodiment 4 Conventional 4 C 53.3 1.09 1.05 0.9454.4 1.10 1.08 0.98 D 57.5 1.07 1.02 0.91 58.6 1.09 1.06 0.95 E 61.21.06 0.99 0.88 62.5 1.09 1.05 0.95 F 65.3 1.04 0.97 0.86 66.5 1.08 1.060.95 G 70.4 1.02 0.94 0.82 71.5 1.07 1.04 0.94 Embodiment 3 Conventional3 C 52.3 1.11 1.07 0.96 53.5 1.12 1.09 1.00 D 56.4 1.09 1.04 0.92 57.61.11 1.08 0.97 E 60.2 1.08 1.01 0.90 61.5 1.11 1.07 0.96 F 64.2 1.060.99 0.87 65.5 1.10 1.07 0.97 G 69.4 1.03 0.95 0.84 70.5 1.09 1.05 0.95Embodiment 5 Conventional 5 C 52.8 1.10 1.06 0.95 54.0 1.11 1.09 0.99 D56.9 1.08 1.03 0.91 58.1 1.10 1.07 0.96 E 60.7 1.07 1.00 0.89 62.0 1.101.06 0.96 F 64.8 1.05 0.98 0.86 66.0 1.09 1.06 0.96 G 69.9 1.02 0.940.83 71.0 1.08 1.04 0.95

FIG. 9 is a graph of the ratio of (MB M/L/Overall A/P) vs. Overall A/Pfor the prostheses described above with respect to FIG. 6. FIG. 10 is agraph of the ratio of (B-B M/L/Overall A/P) vs. Overall A/P for theprostheses described above with respect to FIG. 7. FIG. 11 is a graph ofthe ratio of (Posterior M/L/Overall A/P) vs. Overall A/P for theprostheses described above with respect to FIG. 8.

Table 7 below sets forth the results of a first order equation fit toeach of the data sets shown in FIGS. 9, 10, and 11 as well as for thedata sets of Embodiments 3 and 4 and Conventional 3 and 4 in Table 6.

TABLE 7 Ratio Ratio Ratio (Posterior M/L (Mid-box M/L (B-B M/L vs.Overall vs. Overall vs. Overall A/p) vs. A/P) vs. A/P) vs. Overall A/POverall A/P Overall A/P Best Fit Best Fit Best Fit Regression RegressionRegression Line Line Line Implant Slope y-Intercept Slope y-InterceptSlope y-Intercept Conventional 3 −0.0020 1.23 −0.0023 1.21 −0.0023 1.11Conventional 4 −0.0017 1.20 −0.0020 1.18 −0.0020 1.08 Conventional 5−0.0018 1.21 −0.0021 1.20 −0.0022 1.10 Embodiment 3 −0.0044 1.34 −0.00681.42 −0.0071 1.33 Embodiment 4 −0.0041 1.31 −0.0064 1.39 −0.0068 1.30Embodiment 5 −0.0042 1.32 −0.0066 1.41 −0.0069 1.31 Competitive 1−0.0003 1.10 −0.0008 1.11 −0.0004 0.99 Competitive 2 −0.0017 1.20 0.00031.06 −0.0032 1.21 Competitive 3 −0.0013 1.15 −0.0003 1.09 −0.0024 1.14Competitive 4 −0.0016 1.18 −0.0009 1.13 −0.0001 1.07 Competitive 5−0.0032 1.32 −0.0032 1.31 −0.0025 1.15 Competitive 6 −0.0001 1.08 0.00011.06 0.0010 0.94 Competitive 7 −0.0053 1.51 −0.0054 1.43 −0.0024 1.08Competitive 8 0.0001 0.89 0.0004 0.86 0.0006 0.83

From the data in Table 7 it may be seen that there is a difference inthe slopes of the sets of prostheses of Embodiments 3, 4, and 5 ascompared to the slopes of the sets of the known prostheses. Inparticular, it may be seen from the data in Table 7 that the sets ofprostheses of Embodiments 3, 4, and 5 have a narrowing posterior M/Ldimension with increasing A/P size, as indicated by the slope of theratio (posterior M/L/overall A/P) vs. overall A/P being less than−0.0032 for the sets of prostheses of Embodiments 3, 4, and 5 while thecorresponding slope for the known sets of prostheses is greater than orequal to −0.0032, except for the Competitive 7 prosthesis, indicatingthat the sets of prostheses of Embodiments 3, 4, and 5 have anincreasingly more pronounced narrowing of the posterior M/L dimensionwith increasing A/P size. In this manner, the sets of prosthesesdesigned in accordance with the present invention offer a surgeon aunique combination of implant posterior M/L widths with varying A/P sizefor an overall system or set of prostheses, wherein such sets ofprostheses are more anatomically optimized for the female anatomy ascompared with the sets of known prostheses.

Furthermore, it may be seen that there is a significant difference inslope for the sets of prostheses of Embodiments 3, 4, and 5 as comparedwith the slopes of the known sets of prostheses when looking at the MBand B-B M/L dimensions. The magnitudes of the anterior M/L “B-B” valuesfor a given A/P dimension are more pronounced, i.e., the variance inwidth at dimension B-B, namely, an anterior width, over various A/Psizes between the sets of prostheses of Embodiments 3, 4, and 5 and theknown sets of prostheses is more dramatically pronounced. Specifically,the slope of the ratio (B-B M/L/overall A/P) vs. overall A/P is lessthan −0.0032 for the sets of prostheses of Embodiments 3, 4, and 5,while the corresponding slope for the known sets of prostheses isgreater than or equal to −0.0032, indicating that the sets of prosthesesof Embodiments 3, 4, and 5 have increasingly more pronounced narrowingof the B-B M/L dimension with increasing A/P size.

Furthermore, the slope of the ratio (MB M/L/Overall A/P) vs. Overall A/Pis less than −0.0054 for the sets of prostheses of Embodiments 3, 4, and5, while the corresponding slope for the known sets of prostheses isgreater than or equal to −0.0054, indicating that the sets of prosthesesof Embodiments 3, 4, and 5 have increasingly more pronounced narrowingof the B-B M/L dimension with increasing A/P size. Prostheses 50 mayhave slope values for the ratios of MB M/L/Overall A/P vs. Overall A/Pwith increasing A/P size which may be as small as −0.0075, −0.0072,−0.0069, −0.0066, or −0.0063 or as large as −0.0055, −0.0057, −0.0059,or −0.0061. In this manner, the prostheses designed in accordance withthe present invention offer a surgeon a unique combination of implantM/L widths as an overall system of prostheses, wherein such sets ofprostheses are more anatomically optimized for the female anatomy ascompared with the sets of known prostheses.

Referring again to FIG. 9, the range of values for Embodiment 5generally falls within the lines of a conceptual boundary, such as afour-sided polygon, as shown in solid dashed lines. Clearly, no otherknown prostheses have MB M/L/Overall A/P ratios that fall within thisrange of values for the MB M/L/Overall A/P ratios and correspondingOverall A/P dimensions. The polygon is essentially defined by fourpoints defined by coordinates given by (Overall A/P dimension, MBM/L/Overall A/P ratio): A first point or upper left corner (“FirstPoint”)—(52.0, 1.06); A second point or lower left corner (“SecondPoint”)—(52.0, 0.90); A third point or upper right corner (“ThirdPoint”)—(77.0, 1.02); and a fourth point or lower right corner (“FourthPoint”)—(77.0, 0.91). Thus, the upper boundary of the parallelogramdefined by First Point and Third Point may be given by the equation MBM/L/Overall A/P Ratio=−0.0015*Overall A/P+1.14 and the lower boundarydefined by Second Point and Fourth Point may be given by the equation MBM/L/Overall A/P Ratio=0.0002*Overall A/P+0.89.

As another exemplary comparison, the dimensions “A-A” and “Overall A/P”for conventional prostheses (“Conventional 3”, “Conventional 4”, and“Conventional 5” including five increasing sizes C through G) arecompared with corresponding dimensions of a set of prostheses designedin accordance with the present invention (“Embodiment 3”, “Embodiment4”, and “Embodiment 5” including five increasing sizes C through G). Inone embodiment, the values for Conventional 5 and Embodiment 5 may beaverage values of Conventionals 3 and 4 and Embodiments 3 and 4,respectively. These values are presented in Table 8 below.

TABLE 8 SIZE Overall A/P A-A Overall A/P A-A Embodiment 4 Conventional 4C 53.3 41.0 54.4 45.0 D 57.5 42.6 58.6 46.3 E 61.2 43.6 62.5 48.9 F 65.344.9 66.5 51.7 G 70.4 46.1 71.5 56.0 Embodiment 3 Conventional 3 C 52.341.0 53.5 45.0 D 56.4 42.6 57.6 46.4 E 60.2 43.6 61.5 48.5 F 64.2 44.965.5 51.6 G 69.4 46.1 70.5 55.7 Embodiment 5 Conventional 5 C 52.8 41.054.0 45.0 D 56.9 42.6 58.1 46.3 E 60.7 43.6 62.0 48.7 F 64.8 44.9 66.051.7 G 69.9 46.1 71.0 55.8

FIG. 18 is a graph of the dimension A-A M/L vs. overall A/P for thefollowing sets of prostheses, each in increasing sizes C through G:Conventional 5, Embodiment 5, as well as eight other sets of knowncompetitive prostheses, designated Competitive 1, Competitive 2,Competitive 3, Competitive 4, Competitive 5, Competitive 6, Competitive7, and Competitive 8.

Table 9 below sets forth the results of a first order equation fit tothe data sets shown in FIG. 18 as well as for the data sets ofEmbodiments 3 and 4 and Conventional 3 and 4 in Table 8.

TABLE 9 A-A M/L vs. Overall A/P Best Fit Regression Line Implant Slopey-Intercept Conventional 3 0.64 9.66 Conventional 4 0.65 8.59Conventional 5 0.65 9.13 Embodiment 3 0.30 25.78 Embodiment 4 0.30 25.47Embodiment 5 0.30 25.63 Competitive 1 0.54 13.20 Competitive 2 0.4619.33 Competitive 3 0.68 9.93 Competitive 4 0.76 6.05 Competitive 5 0.2830.74 Competitive 6 0.86 2.98 Competitive 7 0.68 6.54 Competitive 8 0.5713.19

From the data in Table 9, it may be seen that there is a difference inthe slopes of the sets of prostheses of Embodiments 3, 4, and 5 ascompared to the slopes of the sets of the known prostheses. Inparticular, it may be seen from the data in Table 9 that the sets ofprostheses of Embodiments 3, 4, and 5 have a narrowing A-A M/L dimensionwith increasing A/P size, as indicated by slopes less than approximately0.46, except for Competitive 5, for example, as opposed to asubstantially parallel or one-to-one relationship between the posteriorM/L dimension and the A/P dimension with increasing A/P size as in thesets of known prostheses, as indicated by slopes greater than or equal0.46. In an exemplary embodiment, the slope of A-A M/L dimension withincreasing A/P size for prostheses 50 is approximately 0.30.

As set forth in Table 10 below, the Overall A/P dimensions and theratios of the dimension “A-A” vs. “Overall A/P” are given forEmbodiments 3, 4, and 5 as well as for conventional prosthesesConventional 3, 4, and 5.

TABLE 10 Ratio (A-A M/L/ Ratio (A-A M/L/ SIZE Overall A/P Overall A/P)Overall A/P Overall A/P) Embodiment 4 Conventional 4 C 53.3 0.77 54.40.83 D 57.5 0.74 58.6 0.79 E 61.2 0.71 62.5 0.78 F 65.3 0.69 66.5 0.78 G70.4 0.66 71.5 0.78 Embodiment 3 Conventional 3 C 52.3 0.78 53.5 0.84 D56.4 0.76 57.6 0.81 E 60.2 0.72 61.5 0.79 F 64.2 0.70 65.5 0.79 G 69.40.66 70.5 0.79 Embodiment 5 Conventional 5 C 52.8 0.78 54.0 0.83 D 56.90.75 58.1 0.80 E 60.7 0.72 62.0 0.78 F 64.8 0.69 66.0 0.78 G 69.9 0.6671.0 0.79

FIG. 19 is a graph of the ratio of (A-A M/L/Overall A/P) vs. Overall A/Pfor the prostheses described above with respect to FIG. 18.

Table 11 below sets forth the results of a first order equation fit tothe data sets shown in FIG. 19 as well as for the data sets ofEmbodiments 3 and 4 and Conventional 3 and 4 in Table 10.

TABLE 11 Ratio (A-A M/L vs. Overall A/P) vs. Overall A/P Best FitRegression Line Implant Slope y-Intercept Conventional 3 −0.0027 0.97Conventional 4 −0.0023 0.94 Conventional 5 −0.0025 0.95 Embodiment 3−0.0071 1.15 Embodiment 4 −0.0067 1.13 Embodiment 5 −0.0069 1.14Competitive 1 −0.0031 0.94 Competitive 2 −0.0049 1.08 Competitive 3−0.0024 0.99 Competitive 4 −0.0016 0.96 Competitive 5 −0.0073 1.24Competitive 6 0.0007 0.77 Competitive 7 −0.0019 0.90 Competitive 8−0.0033 0.99

From the data in Table 11 it may be seen that there is a difference inthe slopes of the sets of prostheses of Embodiments 3, 4, and 5 ascompared to the slopes of the sets of the known prostheses. Inparticular, it may be seen from the data in Table 7 that the sets ofprostheses of Embodiments 3, 4, and 5 have a narrowing A-A M/L dimensionwith increasing A/P size, as indicated by the slope of the ratio (A-AM/L/overall A/P) vs. overall A/P being less than −0.0049, for the setsof prostheses of Embodiments 3, 4, and 5 while the corresponding slopefor the known sets of prostheses is greater than or equal to −0.0049,except for the Competitive 5 prosthesis, indicating that the sets ofprostheses of Embodiments 3, 4, and 5 have an increasingly morepronounced narrowing of the A-A M/L dimension with increasing A/P size.In this manner, the sets of prostheses designed in accordance with thepresent invention offer a surgeon a unique combination of implant A-AM/L widths with varying A/P size for an overall system or set ofprostheses, wherein such sets of prostheses are more anatomicallyoptimized for the female anatomy as compared with the sets of knownprostheses.

Referring again to FIG. 18, the range of values for Embodiment 5generally falls below the line of a conceptual boundary. The boundarymay be defined by two points defined by coordinates given by (OverallA/P dimension, A-A M/L dimension): a First Point (52.0, 40.3) and aSecond Point (77.0, 51.8). Thus, the boundary defines a line given bythe following equation: A-A M/L=0.46*Overall A/P+16.38.

Referring again to FIG. 19, the range of values for Embodiment 5generally falls below the line of a conceptual boundary. The boundarymay be defined by two points defined by coordinates given by (OverallA/P dimension, A-A M/L/Overall A/P ratio): a First Point (52.0, 0.78)and a Second Point (77.0, 0.67). Thus, the boundary defines a line givenby the following equation: A-A M/L/Overall A/P=−0.0041*Overall A/P+0.99.

Another way of characterizing the design of the present prostheses is bydistal taper angle, “DT”. As used herein and referring to FIG. 12, inwhich the profile 86 of prosthesis 50 is superimposed upon profile 88 ofa known prosthesis, the distal taper angle “DT” is the angle between twolines on opposite sides of the prosthesis each connecting a point 90 onthe edge of the anterior distal chamfer, i.e., along dimension “B-B” anda point 92 on the edge of the posterior distal chamfer, i.e., alongdimension “C-C”. In FIG. 12, distal taper angles DT₁ and DT₂ forprosthesis 50 and for a known prosthesis are illustrated, respectively.It may be seen from FIG. 12 that the distal taper angle DT₁ forprosthesis 50 is greater than the distal taper angle DT₂ for the knownprosthesis.

FIG. 13 is a chart of distal taper angle vs. overall A/P for several ofthe prostheses described above. As before, a first order curve fit wasapplied to the data in FIG. 13 and the results are set forth below inTable 12.

TABLE 12 Distal Taper Angle vs. Overall A/P Best fit regression lineEquation Slope Conventional 3 y = 0.01x + 18.72 0.01 Conventional 4 y =0.01x + 18.79 0.01 Conventional 5 y = 0.01x + 17.75 0.01 Embodiment 3 y= 0.28x + 7.10 0.28 Embodiment 4 y = 0.28x + 6.80 0.28 Embodiment 5 y =0.28x + 6.95 0.28 Competitive 1 y = −0.15x + 24.81 −0.15 Competitive 2 y= 0.20x + 3.04 0.20 Competitive 3 y = −0.08x + 19.43 −0.08 Competitive 4y = −0.24x + 18.77 −0.24 Competitive 5 y = −0.18x + 33.07 −0.18Competitive 6 y = −0.19x + 21.99 −0.19 Competitive 7 y = −0.48x + 67.89−0.48 Competitive 8 y = −0.06x + 9.37 −0.06

As may be seen from the data in Table 12, the ratio between distal taperangle and overall A/P of the prostheses of Embodiments 3-5 differs fromthe known prostheses. In particular, the foregoing data indicates thatprostheses of Embodiments 3-5 have a more pronounced and consistentincrease in distal taper angle with increasing A/P size, as evidenced bya slope of greater than 0.20. Additionally, as may be seen from FIG. 13,the set of prostheses of Embodiment 5 has greater distal taper anglesthroughout the range of sizes of the prostheses than the known sets ofprostheses with positive slopes as set forth in Table 12. Further, thedistal taper angle curve for the set of prostheses of Embodiment 5 has aconsistent upward slope as opposed to the randomized “see-saw” curves orflattened curves of the known sets of prostheses, indicating a moreprecise, parallel or substantial one-to-one relationship between distaltaper angle and overall A/P with increasing A/P size for the set ofprostheses of Embodiment 5. In exemplary embodiments, the slope of thedistal taper angle with increasing A/P size for prostheses 50 may be assmall as approximately 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, or 0.30or as large as approximately 0.42, 0.39, 0.36, or 0.33. In an exemplaryembodiment, the slope of the distal taper angle with increasing A/P sizefor prostheses 50 is approximately 0.28.

As shown in FIG. 13, the range of values for Embodiment 5 generally fallwithin the lines of a conceptual boundary, such as a four-sided polygon,as shown in solid dashed lines. Clearly, no other known prostheses havedistal taper angle values that fall within this range of values for thedistal taper angle and corresponding Overall A/P dimensions. Thefour-sided polygon is essentially defined by four points defined bycoordinates given by (Overall A/P dimension, Distal Taper Angle): Anupper left corner (“1B”)—(52.0, 27.0°); A lower left corner (“4”)—(58.0,22.5°); An upper right corner (“2”)—(77.0, 32.0°); and a lower rightcorner (“3”)—(77.0, 26.0°). Alternatively, the upper left corner may beat coordinates (52.0, 34.0°) (“1A”). Alternatively, points 1A, 1B, 2, 3,and 4 define a five-sided polygon which defines the conceptual boundary.The distal taper angles for Embodiment 5 may be approximately equal toor greater than 21°. The values of distal taper angles for prostheses 50may be as small as approximately 21°, 22°, 23°, 25°, or 27, as large asapproximately 35°, 33°, 31°, or 29°.

Referring again to FIG. 8, the sets of prostheses may be grouped into astandard aspect ratio category and a non-standard aspect ratio category.As used herein, the term “standard aspect ratio” describes a set ofprostheses which, for overall A/P values ranging from approximately 52.0mm to 77.0 mm, have corresponding posterior M/L dimensions whichgenerally fall between an Upper Boundary and a Lower Boundary. The UpperBoundary and Lower Boundary may be defined by lines having pointsdefined by coordinates given by (Overall A/P dimension, Posterior M/Ldimension). The Upper Boundary may be defined by a line connecting afirst or lower left point (“First Upper Point”)—(52.0, 59.0) and asecond or upper right point (“Second Upper Point”)—(77.0, 83.5). TheLower Boundary may be defined by three exemplary boundaries. In oneexemplary embodiment, Lower Boundary 1 may be defined by a lineconnecting a first or lower left point (“First Lower Point 1”)—(52.0,51.0) and a second or upper right point (“Second Lower Point 1”)—(77.0,73.0). In another exemplary embodiment, Lower Boundary 2 may be definedby a line connecting a first or lower left point (“First Lower Point2”)—(52.0, 53.0) and a second or upper right point (“Second Lower Point2”)—(77.0, 75.0). In yet another exemplary embodiment, Lower Boundary 3may be defined by a line connecting a first or lower left point (“FirstLower Point 3”)—(52.0, 55.0) and a second or upper right point (“SecondLower Point 3”)—(77.0, 77.0). For prostheses having overall A/P valuesranging from approximately 52.0 mm to 77.0 mm, the following equationsmay define the Upper and Lower Boundaries: the Upper Boundary line maybe defined by the following equation: Posterior M/L=0.98*OverallA/P+8.04; the Lower Boundary 1 line may be defined by the followingequation: Posterior M/L=0.88*Overall A/P+5.24; the Lower Boundary 2 linemay be defined by the following equation: Posterior M/L=0.88*OverallA/P+7.24; and the Lower Boundary 3 line may be defined by the followingequation: Posterior M/L=0.88*Overall A/P+9.24.

Referring again to FIG. 11, the Upper Boundary and Lower Boundarydescribed above which are used to define the standard aspect ratiocategory for sets of prostheses may also be used with the posteriorM/L/Overall A/P ratio for overall A/P values ranging from approximately52.0 mm to 77.0 mm. The Upper Boundary and Lower Boundary may be definedby lines having points defined by coordinates given by (Overall A/Pdimension, Posterior M/L/Overall A/P Ratio). The Upper Boundary may bedefined by a line connecting a first or lower left point (“First UpperPoint”)—(52.0, 1.13) and a second or upper right point (“Second UpperPoint”)—(77.0, 1.08). The Lower Boundary may be defined by threeexemplary boundaries. Lower Boundary 1 may be defined by a lineconnecting a first or lower left point (“First Lower Point 1”)—(52.0,0.98) and a second or upper right point (“Second Lower Point 1”)—(77.0,0.95). Lower Boundary 2 may be defined by a line connecting a first orlower left point (“First Lower Point 2”)—(52.0, 1.02) and a second orupper right point (“Second Lower Point 2”)—(77.0, 0.97). Lower Boundary3 may be defined by a line connecting a first or lower left point(“First Lower Point 3”)—(52.0, 1.06) and a second or upper right point(“Second Lower Point 3”)—(77.0, 1.00). For prostheses having overall A/Pvalues ranging from approximately 52.0 mm to 77.0 mm, the followingequations may define the Upper and Lower Boundaries: the Upper Boundaryline may be defined by the following equation: Posterior M/L/OverallA/P=−0.0020*Overall A/P+1.24; the Lower Boundary 1 line may be definedby the following equation: Posterior M/L/Overall A/P=−0.0013*OverallA/P+1.05; the Lower Boundary 2 line may be defined by the followingequation: Posterior M/L/Overall A/P=−0.0018*Overall A/P+1.11; and theLower Boundary 3 line may be defined by the following equation:Posterior M/L/Overall A/P=−0.0023*Overall A/P+1.18.

Referring to FIGS. 8 and 11 and applying the foregoing definition ofstandard aspect ratio, it may be seen that the prostheses described byCompetitive 5, Competitive 7, and Competitive 8 fall within thenon-standard aspect ratio category.

Referring again to FIG. 13, Embodiment 5 has a distal taper anglegreater than or equal to 21°. In contrast, all other standard aspectratio prostheses have a distal taper angle less than 21°.

Referring again to FIG. 6, Embodiment 5 has MB M/L dimensions below theboundary defined by a line connecting the First Point (52.0, 55.0) andthe Third Point (77.0, 78.5). Thus, for the range of Overall A/P valuesbetween 52.0 and 77.0, Embodiment 5 has MB M/L dimensions which fallbelow the line given by the following equation: MB M/L=0.94*OverallA/P+6.12. In contrast, all other standard aspect ratio prostheses haveMB M/L dimensions which fall above the line given by the foregoingequation.

Referring again to FIG. 9, Embodiment 5 has MB M/L/Overall A/P ratiosbelow the boundary defined by a line connecting the First Point (52.0,1.06) and the Third Point (77.0, 1.02). Thus, for the range of OverallA/P values between 52.0 and 77.0, Embodiment 5 has MB M/L/Overall A/Pratios which fall below the line given by the following equation: MBM/L/Overall A/P=−0.0015*Overall A/P+1.14. In contrast, all otherstandard aspect ratio prostheses have MB M/L/Overall A/P ratios whichfall above the line given by the foregoing equation.

Referring again to FIG. 7, Embodiment 5 has B-B M/L dimensions below theboundary defined by a line connecting the First Point (52.0, 50.0) andthe Second Point (77.0, 70.5). Thus, for the range of Overall A/P valuesbetween 52.0 and 77.0, Embodiment 5 has B-B M/L dimensions which fallbelow the line given by the following equation: B-B M/L=0.82*OverallA/P+7.36. In contrast, all other standard aspect ratio prostheses haveB-B M/L dimensions which fall above the line given by the foregoingequation.

Referring again to FIG. 10, Embodiment 5 has B-B M/L/Overall A/P ratiosbelow the boundary defined by a line connecting the First Point (52.0,0.96) and the Second Point (77.0, 0.92). Thus, for the range of OverallA/P values between 52.0 and 77.0, Embodiment 5 has B-B M/L/Overall A/Pratios which fall below the line given by the following equation: B-BM/L/Overall A/P=−0.0018*Overall A/P+1.06. In contrast, all otherstandard aspect ratio prostheses have B-B M/L/Overall A/P ratios whichfall above the line given by the foregoing equation.

Referring again to FIG. 18, Embodiment 5 has A-A M/L dimensions belowthe boundary defined by a line connecting the Third Point (52.0, 40.1)and the Fourth Point (77.0, 53.5). Thus, for the range of Overall A/Pvalues between 52.0 and 77.0, Embodiment 5 has A-A M/L dimensions whichfall below the line given by the following equation: A-AM/L=0.54*Overall A/P+12.23. In contrast, all other standard aspect ratioprostheses have A-A M/L dimensions which fall above the line given bythe foregoing equation.

Referring again to FIG. 19, Embodiment 5 has A-A M/L/Overall A/P ratiosbelow the boundary defined by a line connecting the Third Point (52.0,0.77) and the Fourth Point (77.0, 0.69). Thus, for the range of OverallA/P values between 52.0 and 77.0, Embodiment 5 has A-A M/L/Overall A/Pratios which fall below the line given by the following equation: A-AM/L/Overall A/P=−0.0031*Overall A/P+0.93. In contrast, all otherstandard aspect ratio prostheses have A-A M/L/Overall A/P ratios whichfall above the line given by the foregoing equation.

Referring again to Table 5, Embodiments 3-5 have slopes of Posterior M/Ldimension with increasing A/P size which are less than 0.98. Prostheses50 may have slope values for the Posterior M/L dimension with increasingA/P size which may be as small as approximately 0.50, 0.55, 0.60, or0.65 or as large as approximately 0.96, 0.95, 0.94, 0.91, 0.88, 0.85,0.84, 0.83, 0.81, 0.80, 0.75, or 0.70. In contrast, all other standardaspect ratio prostheses have slopes of Posterior M/L dimension withincreasing A/P size which are greater than or equal to 0.98.

Referring still to Table 5, Embodiments 3-5 have slopes of MB M/Ldimension with increasing A/P size which are less than 0.91. Prostheses50 may have slope values for the MB M/L dimension with increasing A/Psize which may be as small as approximately 0.40, 0.45, 0.50, 0.55, or0.57 or as large as approximately 0.90, 0.89, 0.87, 0.84, 0.81, 0.79,0.76, 0.75, 0.74, 0.73, 0.72, 0.71, 0.70, 0.65, or 0.60. In contrast,all other standard aspect ratio prostheses have slopes of MB M/Ldimension with increasing A/P size which are greater than or equal to0.91.

Referring again to Table 5, Embodiments 3-5 have slopes of B-B M/Ldimension with increasing A/P size which are less than 0.80. Prostheses50 may have slope values for the B-B M/L dimension with increasing A/Psize which may be as small as approximately 0.30, 0.35, 0.40, or 0.45 oras large as 0.79, 0.78, 0.77, 0.76, 0.75, 0.74, 0.72, 0.70, 0.65, 0.60,or 0.50. In contrast, all other standard aspect ratio prostheses haveslopes of B-B M/L dimension with increasing A/P size which are greaterthan or equal to 0.80.

Referring to Table 9, Embodiments 3-5 have slopes of A-A M/L dimensionwith increasing A/P size which are less than 0.46. Prostheses 50 mayhave slope values for the A-A M/L dimension with increasing A/P sizewhich may be as small as 0.15, 0.20, 0.25, or 0.30 or as large as 0.45,0.44, 0.42, 0.40, 0.37, 0.34, or 0.31. In contrast, all other standardaspect ratio prostheses have slopes of A-A M/L dimension with increasingA/P size which are greater than or equal to 0.46.

Referring to Table 7, Embodiments 3-5 have slopes for the ratios ofPosterior M/L/Overall A/P vs. Overall A/P with increasing A/P size whichare less than −0.0020. Prostheses 50 may have slope values for theratios of Posterior M/L/Overall A/P vs. Overall A/P with increasing A/Psize which may be as small as −0.0060, −0.0055, −0.0050, −0.0045,−0.0040 or as large as −0.0021, −0.0022, −0.0025, −0.0030, or −0.0035.In contrast, all other standard aspect ratio prostheses have slopes forthe ratios of Posterior M/L/Overall A/P vs. Overall A/P with increasingA/P size which are greater than or equal to −0.0020.

Referring again to Table 7, Embodiments 3-5 have slopes for the ratiosof MB M/L/Overall A/P vs. Overall A/P with increasing A/P size which areless than −0.0023. Prostheses 50 may have slope values for the ratios ofMB M/L/Overall A/P vs. Overall A/P with increasing A/P size which may beas small as −0.0075, −0.0072, −0.0069, −0.0066, or −0.0063 or as largeas −0.0022, −0.0025, −0.0030, −0.0035, −0.0040, −0.0045, −0.0050,−0.0055, or −0.0060. In contrast, all other standard aspect ratioprostheses have slopes for the ratios of MB M/L/Overall A/P vs. OverallA/P with increasing A/P size which are greater than or equal to −0.0023.

Referring again to Table 7, Embodiments 3-5 have slopes for the ratiosof B-B M/L/Overall A/P vs. Overall A/P with increasing A/P size whichare less than −0.0032. Prostheses 50 may have slope values for theratios of B-B M/L/Overall A/P vs. Overall A/P with increasing A/P sizewhich may be as small as −0.0085, −0.0080, −0.0075, or −0.0070 or aslarge as −0.0031, −0.0032, −0.0034, −0.0037, −0.0040, −0.0045, −0.0050,−0.0055, −0.0060, or −0.0065. In an exemplary embodiment, the slopevalue for the ratio of B-B M/L/Overall A/P vs. Overall A/P withincreasing A/P size is approximately −0.0069. In another exemplaryembodiment, the slope value for the ratio of B-B M/L/Overall A/P vs.Overall A/P with increasing A/P size is approximately −0.0068. In yetanother exemplary embodiment, the slope value for the ratio of B-BM/L/Overall A/P vs. Overall A/P with increasing A/P size isapproximately −0.0071. In contrast, all other prostheses have slopes forthe ratios of B-B M/L/Overall A/P vs. Overall A/P with increasing A/Psize which are greater than or equal to −0.0032.

Referring again to Table 11, Embodiments 3-5 have slopes for the ratiosof A-A M/L/Overall A/P vs. Overall A/P with increasing A/P size whichare less than −0.0049. Prostheses 50 may have slope values for theratios of A-A M/L/Overall A/P vs. Overall A/P with increasing A/P sizewhich may be as small as −0.0080, −0.0075, −0.0070, or −0.0065 or aslarge as −0.0050, −0.0051, −0.0053, −0.0055, or −0.0060. In contrast,all other standard aspect ratio prostheses have slopes for the ratios ofA-A M/L/Overall A/P vs. Overall A/P with increasing A/P size which aregreater than or equal to −0.0049.

In accordance with another aspect of the present invention, theprosthesis 50 includes a recessed or reduced profile patellar sulcus aswell as a thinned or reduced profile anterior flange condyles incomparison with known prostheses to alleviate the potential for thethicknesses of the patellar sulcus and the anterior flange condyles tobe greater than the thickness of the femoral bone which is resectedduring the TKR/TKA procedure.

Referring to FIG. 14, a distal view of prosthesis 50 is shown, includingsulcus 70 disposed between lateral and medial anterior condyles 66 and68, respectively. FIG. 15 is a side view of prosthesis 50, in which theanterior profile of sulcus 70 of prosthesis 50 in accordance with thepresent invention is shown as curve 94, and the anterior profile of thesulcus of a known prosthesis is represented by curve 96. A line parallelto non-articular anterior surface 76 and tangent to curve 94 or 96 at ananterior most point thereof may be used to define dimension D1.Dimension D1 represents the maximum thickness of sulcus 70, i.e., thewidth of sulcus 70 between non-articular anterior surface 76 and ananterior most point along curve 94 or curve 96. As may be seen from FIG.15, curve 94 of sulcus 70 of prosthesis 50 is recessed, or shiftedposteriorly, as compared to curve 96 of the sulcus of a knownprosthesis, wherein dimension D1 of prosthesis 50 is less than dimensionD1 of the known prosthesis. Advantageously, recessing the patellarsulcus 70 of prostheses 50 will allow the patella to articulate slightlymore posterior than in known prostheses which will reduce the likelihoodof the thickness of the patellar sulcus to be greater than the thicknessof the femoral bone which is resected when the joint is in extension andearly flexion.

Referring to FIG. 16, the anterior profile of lateral or medial anteriorcondyle 66 or 68 of prosthesis 50 in accordance with the presentinvention is shown as curve 102, and the anterior profile of an anteriorcondyle of a known prosthesis is shown as curve 104. Dimension D2represents the maximum thickness, or depth, of one or both of thelateral and medial anterior condyles between non-articular anteriorsurface 76 and a line drawn parallel to surface 76 and tangent to curve102 or curve 104 at an anterior most point thereof. As may be seen fromFIG. 16, curve 102 of at least one of the lateral and medial anteriorcondyles 66 and 68 of prosthesis 50 is recessed, or shifted posteriorly,as compared to curve 104 of the anterior condyles of a known prosthesis,wherein dimension D2 of prosthesis 50 is less than dimension D2 of theknown prosthesis. Advantageously, the reduction of the anterior flangecondyle thickness reduces the anterior flange profile and createssmoother, less abrupt changes in geometry as the condyles blend to theedges of the components while maintaining adequate height to preventsubluxation of the patella.

In Table 13 below, dimensions D1 and D2 described above are shown inaccordance with a set of prostheses 50 (Embodiment 5) compared to aknown set of prostheses (Conventional 5), as well as the differencesbetween dimensions D1 and D2 of the present prosthesis and knownprosthesis. Unless otherwise indicated, all numerical dimensional valuespresented herein are in millimeters (“mm”).

TABLE 13 Differences (Conventional 5 − Embodiment 5 Conventional 5Embodiment 5) SIZE “D1” “D2” “D1” “D2” “D1” “D2” C 2.5 5.1 3.5 6.3 1.01.1 D 2.5 5.3 3.6 6.4 1.0 1.1 E 2.6 5.0 3.6 6.2 1.1 1.2 F 2.5 5.3 3.66.4 1.1 1.1 G 3.2 6.4 4.2 7.3 1.1 0.9

As may be seen from Table 13, the sulcus and condyle thicknesses D1 andD2 respectively, of prostheses of Embodiment 5 are considerably reducedas compared to the known prostheses (Conventional 5). In particular, thesulcus thickness D1 of an exemplary embodiment may range from about 2.5mm to 3.2 mm and the condyle thickness D2 may range from about 5.0 mm to6.4 mm. In exemplary embodiments, the sulcus thickness D1 of prostheses50 may be as small as approximately 2.5, 2.6, 2.7, or 2.8 mm or as largeas approximately 3.2, 3.1, 3.0, or 2.9 mm. In exemplary embodiments, thecondyle thickness D2 of prostheses 50 may be as small as approximately4.0, 4.3, 4.7, 5.0, 5.2, 5.4, or 5.6 mm or as large as approximately6.4, 6.2, 6.1, 6.0, or 5.8 mm. As such, in an example, a ratio of themaximum condylar thickness D2 to the maximum sulcus thickness D1 can bein the range of 1.92:1 to 2.12:1, as is evident from Table 13. Inanother example, the maximum thickness D2 of the condyle is 1.92 to 2.12times greater than the maximum thickness D1 of the sulcus, as is evidentfrom Table 13. In yet another example, the maximum patellar sulcusthickness D1 of Embodiment 5 is less than the maximum patellar sulcusthickness D1 of Conventional 5 by 23.8 percent to 30.6 percent and themaximum condylar thickness D2 of Embodiment 5 is less than the maximumcondylar thickness D2 of Conventional 5 by 12.3 percent to 19.4 percent,as is evident from Table 13.

The present prostheses further include a modified patellar sulcustracking to further optimize conformance of the prostheses with femaleanatomy. The Q-angle (“quadriceps angle”) is formed in the frontal planeby a pair of line segments, one extending from the tibial tubercle tothe middle of the patella and the other extending from the middle of thepatella to the anterior superior iliac spine (ASIS). In adults, theQ-angle is typically 14° for males and 17° for females, wherein theQ-angle for females is approximately 3° more lateral than that of males.Responsive to this observation, and as described in detail below, theend point of the patellar sulcus 70 of prostheses 50 is shifted 3°laterally with respect to known prostheses, i.e., in an exemplaryembodiment, lateralization angle 108 is approximately 7° in FIG. 17A andapproximately 10° in FIG. 17B.

FIGS. 17A and 17B show A/P views of a known prosthesis and prosthesis50, respectively, with simulated patellas shown in FIGS. 17A and 17B ascircular structures “PA” superimposed upon the anterior flanges of theprostheses. During articulation of the prosthesis, the patella willtrack within the patellar sulcus of the prosthesis. Referring to FIGS.15, 17A, and 17B, the vertex 106 of lateralization angle 108 (FIGS. 17Aand 17B) is located at the intersection of a plane coincident with theflat, distal non articular surface 80 (FIG. 15) of prosthesis 50 withcurve 94 (FIG. 15) of the patellar sulcus 70. From vertex 106, line 110is drawn orthogonal to distal non articular surface 80, and the endpoint 112 of the patellar sulcus 70 is defined as the center of thepatellar sulcus 70 at a line 114 parallel to distal non articularsurface 80 and disposed at varying heights “H” in accordance withvarying prosthesis size. Line 118 connects vertex 106 with end point 112of the patellar sulcus and the angle originating at vertex 106 betweenlines 110 and 118 is lateralization angle 108. For a range of sizes Cthrough G of prostheses represented in FIGS. 17A and 17B having varyingheight dimensions “H” indicated in Table 14 below between distal nonarticular surface 80 and line 114, the distance between line 110 andpoint 112, i.e., the lateralization distance, also varies as indicatedin FIGS. 17A and 17B, wherein the foregoing data is summarized below inTable 14 for a known prosthesis (Conventional 1, FIG. 17A) andprosthesis 50 (Embodiment 1, FIG. 17B). Unless otherwise indicated, allnumerical dimensional values presented herein are in millimeters (“mm”).

TABLE 14 Vertical Position Height Lateralization Distance Change FromDistal Conventional 1 Embodiment 1 Conventional 1 − Size Face (H) (FIG.17A) (FIG. 17B) Embodiment 1 C 28.6 3.8 5.3 1.5 D 31.3 4.1 5.8 1.7 E31.3 4.2 5.8 1.6 F 34.8 4.5 6.5 2.0 G 38.8 5.0 7.0 2.0

As may be seen from Table 14, the lateralization distance of prostheses50 is increased with respect to known prostheses to optimize patellatracking with the prostheses to more closely conform to female anatomy.In an exemplary embodiment, the lateralization distance is greater than5.0 mm. In an exemplary embodiment, the lateralization distance forprostheses 50 may be as small as approximately 5.0, 5.3, 5.6, or 5.9 mmor as large as approximately 7.0, 6.7, 6.4, or 6.1 mm.

While this invention has been described as having exemplary designs, thepresent invention can be further modified within the spirit and scope ofthis disclosure. This application is therefore intended to cover anyvariations, uses, or adaptations of the invention using its generalprinciples. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

What is claimed is:
 1. A distal femoral prosthesis, comprising: a distalportion including a planar distal non-articular surface and an opposingdistal articular surface; and an anterior portion including lateral andmedial anterior condyles each defining an anterior articular surface, apatellar sulcus defined between said condyles, and an anteriornon-articular surface, said patellar sulcus having a maximum thicknessbetween 2.5 mm and 3.2 mm between an anterior most point on said sulcusand said anterior non-articular surface, and at least one of saidcondyles having a maximum thickness between 5.0 mm and 6.4 mm between ananterior most point on said anterior articular surface of said condyleand said anterior non-articular surface; wherein a ratio of the maximumcondylar thickness to the maximum patellar sulcus thickness is in therange of 1.92:1 to 2.12:1.
 2. The distal femoral prosthesis of claim 1,wherein said maximum thickness of said patellar sulcus is in the rangeof 2.6 mm to 3.1 mm.
 3. The distal femoral prosthesis of claim 1,wherein said maximum thickness of said patellar sulcus is 3.2 mm.
 4. Thedistal femoral prosthesis of claim 1, further comprising medial andlateral posterior condyles each having a posterior non-articularsurface.
 5. The distal femoral prosthesis of claim 4, furthercomprising: a distal anterior non-articular surface connecting saidplanar distal non-articular surface and said anterior non-articularsurfaces; and distal posterior non-articular surfaces connecting saidplanar distal non-articular surface and said posterior non-articularsurfaces.
 6. A distal femoral prosthesis, comprising: a distal portionincluding a planar distal non-articular surface and an opposing distalarticular surface; an anterior portion including lateral and medialanterior condyles each defining an anterior articular surface, and ananterior non-articular surface, at least one of said condyles having amaximum thickness between 5.0 mm and 6.4 mm between an anterior mostpoint on said anterior articular surface of said condyle and saidanterior non-articular surface; and a patellar sulcus defined betweensaid condyles, said patellar sulcus having a maximum thickness betweenan anterior most point on said sulcus and said anterior non-articularsurface, wherein said maximum thickness of said condyles is 1.92 to 2.12times greater than said maximum thickness of said sulcus.
 7. The distalfemoral prosthesis of claim 6, wherein said maximum thickness of the atleast one of said condyles is in the range of 5.0 mm to 6.1 mm.
 8. Thedistal femoral prosthesis of claim 6, wherein said maximum thickness ofthe at least one of said condyles is 5.0 mm.
 9. The distal femoralprosthesis of claim 6, wherein said maximum thickness of the at leastone of said condyles is 6.4 mm.
 10. The distal femoral prosthesis ofclaim 6, wherein said maximum thickness of the at least one of saidcondyles is in the range of 5.2 mm to 6.0 mm.
 11. The distal femoralprosthesis of claim 6, wherein said maximum thickness of the at leastone of said condyles is 5.3 mm.
 12. The distal femoral prosthesis ofclaim 6, further comprising medial and lateral posterior condyles eachhaving a posterior non-articular surface.
 13. The distal femoralprosthesis of claim 12, further comprising: a distal anteriornon-articular surface connecting said planar distal non-articularsurface and said anterior non-articular surfaces; and distal posteriornon-articular surfaces connecting said planar distal non-articularsurface and said posterior non-articular surfaces.
 14. A set of distalfemoral prostheses comprising: a first distal femoral prosthesiscomprising: a first distal portion including a first distal articularsurface and a first planar distal non-articular surface; and a firstanterior portion including first lateral and medial anterior condyleseach defining a first anterior articular surface, a first patellarsulcus defined between said condyles, and a first anterior non-articularsurface, said first patellar sulcus having a first thickness definedbetween an anterior most point on said first patellar sulcus and saidfirst anterior non-articular surface; and a second distal femoralprosthesis comparable in overall size to said first distal femoralprosthesis, said second distal femoral prosthesis comprising: a seconddistal portion including a second distal articular surface and a secondplanar distal non-articular surface; and a second anterior portionincluding second lateral and medial anterior condyles each defining asecond anterior articular surface, a second patellar sulcus definedbetween said condyles, and a second anterior non-articular surface, saidsecond patellar sulcus having a second thickness defined between ananterior most point on said second patellar sulcus and said secondanterior non-articular surface, wherein said second thickness is lessthan said first thickness by 23.8 percent to 30.6 percent, and whereinat least one of said first lateral and medial anterior condyles of saidfirst distal femoral prosthesis has a third thickness defined between ananterior most point on said first anterior articular surface of saidfirst lateral or medial condyle and said first anterior non-articularsurface, at least one of said second lateral and medial anteriorcondyles of said second distal femoral prosthesis has a fourth thicknessdefined between an anterior most point on said second anterior articularsurface of said second lateral or medial condyle and said secondanterior non-articular surface, and said fourth thickness is less thansaid third thickness by 12.3 percent to 19.4 percent.
 15. The set ofdistal femoral prostheses of claim 14, wherein said second thickness isin the range of 2.5 mm to 3.2 mm.
 16. The set of distal femoralprostheses of claim 14, wherein said fourth thickness is in the range of5.0 mm to 6.4 mm.
 17. The set of distal femoral prostheses of claim 14,wherein said second thickness is less than said first thickness by atleast 24 percent.
 18. The set of distal femoral prosthesis of claim 14,wherein said second thickness is less than said first thickness by nomore than 30 percent.